( Reaffirmed 2000 )

IS:7661-1975

Indian Standard
SPECIFICATION FOR 4-AMINOAZOBENZENE
Dye Intermediates
Chairman SHRI JOUINDER SINGH Members SHRI P. B. BHATTACHARJEE Luxmi Narayan Dyestuff & Chemical Works Pvt Ltd, Calcutta Atic Industries Ltd, Bulsar SHRI B. M. BRARME Development Commissioner, Small Scale Industries, SHRI M. K. CHITRE New Delhi SRRI G. G. SUTAONE ( Alternate ) Amar Dye-Chem Ltd, Bombay SHRI G. A. KULKARNI SHRI S. V. DESAI (Alternate) Atul Products Ltd, Bulsar SHRI S. M. MERTA SHRI M. V. DESAI ( Alternate ) Suhrid Geigy Ltd, Baroda DR 0. P. MITTAL SHRI N. G. AMIN ( Alternate) SHRI B. M. PATEL I. C. I. ( India) Pvt Ltd, Calcutta SRRI Y. R. MEHTA ( Alternate ) Indian Dyestuff Industries Ltd, Bombay SRRI RAJENDRA SHANKAR SHRI M. S. TAWAKLEY ( Alternate ) DR R. J. RATHI Sudarshan Chemical Industries Pvt Ltd, Poona SHRI K. L. RATHI ( Alternate ) SHRI SANTOKH SINGR National Chemical Industries Pvt Ltd, New Delhi SHRI KTJLWANT SINQH ( Alternate ) SHRI S. J. SHAH Indian Chemical Manufacturers' Association, Calcutta SHRI M. B. MEHTA ( Alternate ) Indian Drugs & Pharmaceuticals Ltd, New Delhi DR D. R. SRIDHAR DR R. N. DEAR ( Alternate ) DA P. V. SUBRAMANIAM Colour-Chem Ltd, Bombay SHRI MUKUND TURAKHIA The Dyestuffs Manufacturers Association of India, Bombay SHRI ANIL MEHTA ( Alternate ) SHRI V. G. UPADHYE Synthofine Chemicals of India Pvt Ltd, Bombay ( Continued on Page 2 ) 0 INDIAN Copyright 1975 INSTITUTION Directorate Delhi

Sectional Committee,
RePresenting

CDC 46

General of Technical

Development,

New

STANDARDS

This publication is protected under the Indian Copyright Act ( XIV of 1957 ) and reproduction is whole or in part by any means except with written permission of the publisher shall be deemed to be an infringemmt of copyright under the said Act.

IS : 7661- 1975 ( Contifzuedffom~ape
Members DR H. P. VAX-DREWALA DR P. N. PANDIT ( &tern&e) DR G. M. SAXENA, Director ( Chem ) 1) Refiresenting Hindustan Organic ( Maharashtra ) Chemicals Ltd, Rasayani

Director ~General, IS1 ( Ex-o#cio Member )

Secretary SHRI NARESH K. SHARBU Assistant Director ( Chem ), IS1

Panel

for

4-Aminophenol

and 4-Aminoazobenzene,

CDC 46 : P 5

Convener SERI S. M. MERTA Members DR N. F. DESAI SHR~ G. A. KULKARNI SHRI V. K. MENON (Alternate) DR I. F. NIZAE~I DR P. B. SATTUR DR D. R. SRIDHAR DR G. RAMANA RAO ( Alternate SHRI M. S. TAWAELEY DR S. S. GUPTE ( Alfernale ) Sandoz (India ) Ltd, Bombay Amar Dye-Chem Ltd, Bombay Suly Chemicals, Baroda Regional Research Laboratory ( CSIR ), Hyderabad Indian Drugs & Pharmaceuticals Ltd, New Delhi ) Indian Dyestuff Industries Ltd, Bombay Atul Products Ltd, Bulsar

2

IS : 7661-1975

Indian Standard
SPECIFICATION FOR 4-AMINOAZOBENZENE
0. FOREWORD
0.1 This
Indian Standard -was adopted by the Indian Standards Institution on 6 May 1975, after the draft finalized by the Dye Intermediates Sectional Committee had been approved by the Chemical Division Council. 0.2 4-Aminoazobenzene ( Ct2HtrNs ) is an important starting material for many diazo dyes. It is also known as 4-benzene azoaniline. It has the following structural formula:

4-AMINOAZOBENZENE ( Molecular Mass 197'1 ) 0.3 For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordThe number of significant places retained in ance with IS : 2-1960*. the rounded off value should be the same as that of the specified value in this standard.

1. SCOPE
1.1 This standard prescribes the requirements sampling and test for 4-aminoazobenzene. 2. REQUIREMENTS 2.1 Description - The material shall be in the form of yellowish reddish orange powder and free from visible impurities.
*Rules for rounding off numerical values ( m&cd ) .

and the

methods

of

to

3

IS : 7661- 1975 2.2 The material Table 1.
TABLE
SL No.

shall

also

comply

with

the

requirements

given

in

1 REQUIREMENTS

FOR

4-AMINOAZOBENZENE
REQUIREMENT METHOD OF TEST, REF TO CL No. IN APPENDIX A (4)

CHARACTERISTIC

(1) i)

(2)
Assay, percent by mass, Min Aniline content, percent by mass, Max percent by P-Aminoazobenzene mass, Max content,

(3) 90

A-l A-2 A-3 A-4 A-5

ii) iii) iv) v)

0.2 2 5 119°C

Insolubles in diazo solution, percent by mass, Max ( on 100 percent basis ) Melting point, Min

3. PACKING

AND

MARKING

3.1 Packing - The material shall be packed in steel drums ( see IS : 2552-1970") lined with suitable polyethylene film, or as agreed to hetween
the purchaser and the supplier. container shall be securely closed the ~following information: ' and his recognized and shall bear 3.2 Marking-Each legibly and indelibly a> Name b) Name c) Batch

of the material; of the manufacturer, number; worded as under: AND CONTACT MAY RESULT IS1 Certification trade-mark, if any;

d) Gross, net and tare mass; and notice 4 The minimum cautionary

` POISONOUS
WITH SKIN IN BLADDER 3.2.1 Mark. The containers

INHALATION ! REPEATED ABSORPTION TUMORS .' may also be marked

! AVOID

with the

NOTE - The use of the IS1 Certification Mark is governed by the provisions of the Indian Standards Institution ( Certification Marks ) Act and the Rules and RegulaThe ISI Mark on products covered by an Indian Standard tions made thereunder. conveys the assurance that they have been produced to comply with the requiremen s of that standard under a well-defined system of inspection, testing and quality control *Specification for steel drums ( galvanized and ungalvanized ) (Jirst revision ).

4

IS : 7661- 1975
which is devised and supervised by IS1 and operated by the producer. ISI marked products are also continuously checked by IS1 for conformity to that standard as a further safeguard. Details of conditions under which a licence for the use of the IS1 Certification Mark may be granted to manufacturers or processors, maybe obtained from the Indian Standards Institution. 4. SAMPLING

4.1 Representative
4.2

samples in 3 of IS : 5299-1969*.

of the material

shall be drawn as prescribed

Number of Tests 4.2.1 Test
shall be conducted on each of the individual

for assay samples separately.

4.2.2 Tests for the determination of remaining characteristics, namely, aniline content , 2-aminoazobenzene content, insolubles in diazo solution, and melting point shall be conducted on the composite sample. 4.3

Criteria for Conformity

4.3.1 For Individual Samples - The lot shall be declared as conforming to the requirement of assay, if each of the individual test results satisfies the relevant requirement giver1 in Table 1.
4.3.2 For Composite Sample - For declaring the conformity of the lot to the requirements of all other characteristics tested on the composite sample ( see 4.2.2 ), the test results for each of the characteristics shall satisfy the relevant requirements given in Table 1. 5. TEST METHODS

5.1 Tests shall be
Appendix A. co1 4 of Table

conducted according to the methods prescribed Reference to relevant clauses of Appendix A is given 1.

in in

5.2 Quality of Reagents - Unlessspecified otherwise, pure chemicals and distilled water (see IS : 1070-19607 ) shall be employed in tests. NOTE - ` Pure chemicals ' shall mean chemicals that ado not contain impurities
which affect the results of analysis.

APPENDIX A ( Tuble 1, and Clause 5.1)
METHODS A-l. ASSAY
shall be assayed by either of the two methods given

OF TEST FOR 4AMINOAZOBENZEkE

A-1.0 The sample in A-l.1 and A-1.2.

*Methods of sampling and tests for dye intermediates. tspecification for water, distilled quality ( revised). 5

IS : 7661- 1975 A-l.1 Assay by Diazotization A-1.1.0 Outline of th Method - Direct titration involving diazotization of the amine under acidic conditions with standard sodium nitrite solution using starch and potassium iodide test papers as external indicator. A-1.1.1 Reagents A-1.1.1.1 Glacial acetic acid A--1.1.1.2 Concentrated A-1.1.1.3 Potassium
See IS : 695-1967*. acid See IS : 265- 1962t.

hydrochloric

bromide -

solid. 1 N.

A-1.1.1.4 Standard sodium nitrite solution A-1.1.1.5 Starch and potassium

iodide test papers

A-1.1.2 Procedure - Dissolve 5'000 0 g of the sample in 200 ml of glacial acetic acid in a 500-ml conical flask. Heat moderately, if necessary. Cool the contents of the flask externally to 20°C and thereafter transfer Rinse the flask thoroughly with glacial the solution to a 2-litre beaker. Add 25 ml of concentrated hydrochloric acid, 500 ml of acetic acid. While stirring mechanically, titrate water and 5 g of potassium bromide. ( By keepdropwise at about 20°C with standard sodium nitrite solution. ing the solution for a longer time, without addition of sodium nitrite, the material will start crystallizing which should be avoided. ) When about 24 ml of nitrite solution ( corresponding to about 95 percent material ) has been added, start testing on starch and potassium iodide test papers. As the end point is approached, add nitrite in 0'1 ml and finally in 0'05 ml The end point is reached when an immediate faint blueincrements. coloured ring appears, which can be obtained repeatedly during the Record period of 10 minutes without further addition of nitrite solution. the volume of titre used as V. Preserve the diazo solution obtained for the test in A-4. A-1.1.3 Calculation Total amine, percent by mass = where V = volume in ml of sodium nitrite solution required for the sample, N = normality of sodium nitrite solution, and M = mass in g of~the material taken for the test.
*Specification tSpecification for acetic acid ( (jirsr reoision ). for hydrochloric acid (revised).

' Xs

`9?

( let this value be D )

6

IS : 7661- 1975 A-1.1.4 Reporting - Total amine content determined shall be corrected by the amount of aniline determined under A-2, when reporting the results: Total amine content ( excluding aniline ), calculated from diazotization value, per= D-(Ex cent by mass where D = total amine content inclusive of ~aniline ( see A-1.1.3 ), percent by mass ( on molecular mass 197'1 ); and
E = aniline

2'12)

content ( see A-2.3.2 ), molecular mass 93'12 ). Method

percent

by

mass ( on

A-l.2

Assay by Chromatograpbic

A-1.2.0 Outline of the Method - Assay is done by column chromatographic method. The material is separated chromatographically and determined quantitatively by spectrophotometer. A-1.2.1
Aflparatus Chromatographic Spectrophotometer column -

A-1.2.1.1
A-1.2.1.2

capable of reading at 370 mp.

A-1.2.2

Reagents Toluene Alumina -

A-1.2.2.1

distilled. neutral.
-

A-1.2.2.2 A-1.2.2.3 A-k2.3

I-Aminoa<obenzene

pure.

Procedure

A-1.2.3.1 Weigh accurately about 50 mg of the sample. Transfer the sample to a dry 250-ml flask. To the flask, add about 200 ml of toluene and reflux for half an hour. Cool the solution to room temperature. Transfer the solution to a dry 250-ml volumetric flask. Wash the flask thoroughly with solvent and transfer the washings also to the volumetric flask. Fimlly dilute the solution to the mark and shake well. Prepare an alumina column, using standard neutral alumina and toluene. The height of the alumina column shall be about 20 cm. Load Allow the solution to come down and when the 5 ml of the solution. 7

IS : 7661-

1975

cotton on the alumina is just dry, add about 1 to 2 ml of toluene at a time till the cotton is free of coIour. Then fill the column with toluene. Following bands are observed from bottom to top: a) Avery faint yellow, b) Second c) Main very faint yellow, yellow band. and

Collect the main yellow band in a dry 250-ml volumetric flask. Make up to the mark, shake well and take reading on a spectrophotometer at 370 rnp. A-1.2.4 reference Calculation -Calculate sample as follows: Purity, where D = optical density of the sample taken for the test, density of 1 mg/lOO ml k = constant ( reciprocal of the optical of the reference sample ) , d = dilution factor, and taken for the test. CONTENT M = mass in g of the material A-2. DETERMINATION OF ANILINE percent the purity by comparing with the

by mass = Pxkx M

d

x

100

,

A-2.0 Outline of the Method - After slurrying a known mass of the material with water, aniline is steam-distilled into dilute hydrochloric acid. The distillate containing aniline is diazotized with standard sodium nitrite solution. A-2.1 Apparatus Distillation Condenser Flask 3 litres capacity.

A-2.1.1 A-2.1.2 A-2.2

of not less than 45 cm length.

Reagents Hydrochloric Acid dilute ( 1: 1

A-2.2.1

).
0'5 N.

A-2.2.2
A-2.2.3 A-2.2.4

Concentrated Hydrochloric

A&d -

See IS : 265- 1962*.

Standard Sodium .Nitrite Solution Starch and Potassium

Iodide rest Papers
revised).

*Specification for hydrochloric acid (

IS : 7661- 1975 A-2.3 Procedure Place 100 g of the sample in a ~distillation flask and slurry with 750 ml of water. Connect the side arm of the distillation flask with the condenser. Steam distil the aniline whrle heating the flask from below. Collect the distillate in a 1-litre conical flask containing 100 ml of dilute hydrochloric acid. When about 500 ml of the distillate has been collected, stop distillation and cool the distillate to about 5°C by external cooling. Filter the distillate through filter paper ( Whatman No. 1 or equivalent ) and estimate aniline in the filtrate by diazotization. A-2.3.1 Diazotization - Transfer the filtrate quantitatively to a I-litre Add 25 ml of concentrated hydrochloric acid and 10 g of beaker. potassium bromide. Cool the beaker and the contents to 0 to 2°C in a suitable ice-bath and add a little crushed ice to the beaker. While continuously stirring the contents ~of the beaker, titrate at 0 to 2°C with standard sodium nitrite solution, adding the nitrite solution dropwise through a long stem funnel which ~dips into the solution. As the end point is approached, remove the long stem funnel, wash it thoroughly into the beaker, and add the nitrite solution, with the tip of the burette well under the surface of the solution, in 0'1 ml and finally in 0'05 ml increments. The end point is reached when an immediate faint blue-coloured ring appears which can be obtained repeatedly during the period of 10 min without further addition of nitrite solution. Record the volume of titre used as V.

A-2.3.2 Calculation
Aniline, where V = volume in ml of standard of sodium sodium nitrite solution, for the test, and 4-aminoazobenzene. solution used, percent by mass = ( V 0.4 ) x Jv x 9.3

M

JV = normality

nitrite

M = mass in g of the material
0'4 = the correction factor

taken

for the dissolved

A-3. DETERMINATION

OF 2-AMINOAZOBENZENE

CONTENT

A-3.0 Outline of the Method -

4-Aminoazobenzene and 2-aminoazobenzene on reductiqn with either stannous chloride or zinc and hydrochloric acid, form aniline and p-phenyIenediamine and aniline and o-phenylenediamine respectively. The p-phenyIenediamine and o-phenylenediamine can be distinguished by their behaviour towards the reagent The former does not react, while the latter forms phenanthraquinone. bright yellow precipitate of diphenylene quinoxaline ( C2oHr~Nz ). 9

IS : 7661- 1975 A-3.1 Reagents A-3.1.1 Zinc Dust A-3.1.2 Glacial Acetic Acid A-3.1.3 Acetic Acid Solution A-3.1.4 o-Phenylenediamine A-3.1.5 Hydrochloric Acid 30 percent ( m/v ) . 20 percent ( m/v ). 30 percent ( a/v).

-A-3.1.6 Sodium Bisulphite Solution -

10 g of phenanA-3.1.7 Phenanthraquinone-Bisulfihite Solution -Dissolve thraquinone in 100 ml of glacial acetic acid, heating, if necessary. Pour the clear solution in 1 000 ml of water. The material falls out in a fine state of division. Filter the material and wash with water. Take this already prepared phenanthraquinone in a small dish, add 20 ml of sodium bisulphite solution or for 10 g take 4 g of sodium bisulphite and dissolve in 20 ml of water. The contents of the dish will set soon to an almost white mass. Dissolve the mass in waterand dilute to approximately 2 000 ml and filter. A-3.1.8 Sodium Acetate crystalline.

A-3.2 Procedure A-3.2.1 Suspend 10 g of 4-aminoazobenzene in 150 ml of hydrochloric acid and 1 000 ml of hot water. Stir the solution while moderately heating over a burner. Reduce with sufficient quantity of zinc dust, adding in portions. To the decolourized solution add 150 g of crystalline sodium acetate. Allow it to cool thoroughly, filter and wash with water. Dilute to a known volume ( V ) . o-Phenylenediamine is precipitated in the filtrate as follows: Mix 100 ml ( or a suitable aliquot, according to the contents of o-phenylenediamine ) of the prepared and filtered solution with a few drops of sodium bisulphite solution and 5 ml of 30 percent acetic acid in a conical flask. Dilute with water to about 500 ml. Precipitate the o-phenylenediamine with phenanthraquinonebisulphite solution. A-3.2.1.1 The precipitation of o-phenylenediamine with phenanthraquinone-bisulphite is to be followed under certain conditions because, if too large excess of the reagent is used for the precipitation of o-phenylenediamine, too high results are obtained. Besides, the reaction between phenanthraquinone and o-phenylenediamine should run slowly and proportionately. On this ground, the required quantity of the 10

IS : 7661- 1975 reagent for the precipitation should be ascertained carefully as far as possible. In the best way one can proceed according to the following procedure: First add only 20 ml of phenanthraquinone-bisulphite sohrtion to the ahquot taken. Heat to boil; and boil for 5 min more. Filter a part of the reaction mixture. Divide the filtrate in two parts. One part is mixed with 3 drops of phenanthraquinone-bisulphite solution and the other part is mixed with several millilitres of aqueous solution of o-phenylenediamine. Both the solutions are heated to boil simultaneously and boiled for a little more time. Then acidify with few drops of hydrochloric acid. A sufficient quantity of phenanthraquinone-bisulphite is present if 1 the turbidity obtained with o-phenylenediamine solution is stronger than that obtained with phenanthraquinone-bisulphite solution. Observe the turbidity only after heating the solution to boil. There may-be maximum turbidity with phenanthraquinone-bisulphite solution, but it should not be a flocky separation. Turbidity produced on cooling is not to be considered. If it is found that phenanthraquinone-bisulphite is present boil the main reaction mixture for 5 min without further of the reagent and repeat the test as stated above. If the detects excess phenanthraquinone, it can be assumed that quantity of the reagent has been added. in excess, addition test still sufficient

However, if the test shows the presence of o-phenylenediamine, another 20 ml of phenanthraquinone-bisulphite solution should be added to the main reaction mixture, boiled for 5 to 10 min and tested as above for the presence of excess of the reagent. A-3.2.2 By this way if the quantity of phenanthraquinone-bisulphite solution adequate for complete precipitation of o-phenylenediamine ~has been ascertained, the original reaction mixture is further heated for 1 h in boiling water-bath for completion of conversion. Filter the precipitated condensation product through a folded filter paper. Transfer the precipitate to a beaker by means of 1 percent hydrochloric acid. Boil for some time. Filter the precipitate through a tared G-4 sintered glass or Gooch crucible. Dry at 100 to 110°C to constant mass. Cool in a desiccator and weigh. A-3.2.3 If ascertaining the quantity of phenanthraquinone partial precipitation, the condensation product is coloured strongly. So the first test should be considered as a experiment. Carry out the final experiment by adding the phenanthraquinone-bisulphite solution ( ascertained in the experiment ), taking fresh aliquot of the solution. 11 needs more dark very preliminary quantity of preliminary

IS : 7661- 1975 A-3.3 Calculation 2-Aminoazobenzene, where A = mass in g of the condensation product obtained, V = volume in ml made after reducing the compound, b = volume in ml of the aliquot, and M = mass in g of the material taken for the test. A-4. DETERMINATION OF INSOLUBLES IN DIAZO SOLUTION percent by mass = A x Vx 70'354 5 bxM

A-4.1 Procedure - Observe the clarity of the diazo solution obtained If more than traces of undiazotizable matter remain, filter the in A-1.1.2. solution through a tared G-3 sintered glass crucible, wash thoroughly Dry the crucible with its contents at with water till free from chlorides. 100°C to constant mass. Cool in a desiccator and weigh. A-4.2 Calculation Insolubles in diazo solution, percent by = mass ( on 100 percent basis ) where S = mass in g of the residue, M = mass in g of the material in A-1.1.2, and D = purity of 4-aminoazobenzene A-5. DETERMINATION A-5.1 Determine IS: 5299-1969*. OF MELTING taken for diazotization s x 100 x M 169 u

( see A-1.1.4). POINT as prescribed in 8 of

the melting point of the material

*Methods

of sampling and tests for dye intermediate:.

-12

INDIAN ON

STANDARDS

DYE INTERMEDIATES

IS

:
Nitrobenzene (first reuision ) (fitst rcvi.G~a) Sulphanilic acid, technical @-Naphthol (jir& revision) a-Naphthylamine Aniline, technical 8-Ozynaphthoic p-Nitrotoluene, o-Chloroaniline m-Chloroaniline p-Chloroaniline p-Nitrotoluene-o-sulphonic Acetoacetanilide Acetoacet-o-chloroaniiide +Aminoacetanilide 2,5-Dichloroaniline 2-Nitro-4-chlorotoluene 4, 4'-Dinitrostilbene-2,2'-disulphonic 1-Aminoanthraquinone 2-Aminoanthraquinone Benzanthrone Metanilic acid, technical Methods of sampling and tests for dye intermediates Nitrobenzene-m-sulphonic p-Anisidine p-Toluidine o-Anisidme o-Toluidine v-Nitroanisole Anthraquinone, p-Nitroanisole J-acid Quinizarine,.technical 1,4-Diaminoanthraquinone, 3-Bromobenzanthrone, 3,9-Dibromobenzanthrone, technical technical technical technical acid, sodium salt acid ( disodium salt) acid (jrst revision ) Naphthionic acid ( sodium salt ) (Jirst revision) acid ( bon acid ) technical P'-disulphonic acid

2630-1973 2740-1973 2741-1973 27441964 2833-1973 3229-1973 3242-1965 3562-1965 4265-1967 4334-l 967 4335-1967 4336-1967 4425-1967 4523-1968 4524-1960 4525-1968 4526-1968 4527-1968 4528-1968 5042-1969 5843-1969 5044-1969 5045-1969 5299-1969 5438-1969 5646-1970 5647-1970 5648-1978 5649-1970 6258-1970 6259-1971 6260-1971 62641971 6265-1971 6266-1971 6961-1973 6962-1973

4,4'-Diaminostilbene-2,

IS : 6977-1973 7359-1974 7360-1974 7362-1974 7364-1974 7635-1975 7636-l 975 7637-1975 7641-1975 7642-1975 7643-1975 7644-1975 7645-1975 7646-1975 7647-1975 7661-1975 7686-1975 1,~5-Diaminoanthraquinone, 1-Chloroanthraquinone, 1, 5-Dichloroanthraquinone, Tobias acid m-Nitro-p-toluidine 2-Nitroaniline 4-Chloro-2-toluidine 5-Chloro-2-toluidine 4-Chloro-2-anisidine CAminophenol 4Chloro-2-nitroaniline 3-Nitroaniline Phenyl J-acid, Benzoyl J-acid, technical technical technical technical technical

Acetoacet-P-toluidine 4Aminoazobenzene 3 ( N. N-diethyl ) aminophenol

AMENDMENT

1 NOVEMBER 2003 TO IS 7661:1975 SPECIFICATION FOR 4-AMINOAZOBENZENE
(CASNo.6O-W-3)'at asanalternate

NO.

[ Page 3, Foreword, Structural forn~ula ]-lnseti` the end of structural formula.
[Page 4,7'ablel, method. Sl No. (ii)and(iii), co[4

]--InseIt'&6'

( Page 12, clause A-5.1) -- Insert the following text after A-5.1: LAYER A-6 THIN CHROMATOGRAPHIC DETERMINATION OF IMPURITIES A-6.1 General Impurities are determined by thin layer chromatography. Reference may be made to `IS 5299 : 2001 Methods of sampling and tests for dye intermediates' for details of TLC test method to be followed. However, necessary details of test conditions are given here for guidance only. 1. 2. 3. 4. 5. Product name Sample solution (on IOO$ZO basis) Application/volume Standard Test substance for impurities for spotting 4-Aminoazobenzene
2V0 in acetone

ANALYSIS

FOR

10 j.,dfor sample and 2 @ and 4 IA for impurities Reference standard 1) 2-Aminoazobenzene 2) Aniline (0.05% .Solution in acetone) Silica gel G Toluene : Carbontetrachloride 50 : 50 (Ammonia Atmosphere) 40 min 25 f 5°C 1

6. 7.

Plate type Eluent

8. 9.

Elution time Temperature

.4mend No. 1 to IS 7661:1975 10. Detection spray 11. Evaluation 12. Approx Rf value -- Main band --Impurities : * PDAB solution Semi quantitative 4-Aminoazobenzene Aniline 2-aminoazobenzene : : Rf 0.3 Rf 0.2 Rf 0.4

`P~AB solution

p-Dlmethylamino Methanol:

benzaldehyde

I % solution in (1 :0.5:0.5) Water: 5 N HCI

(PCD1l)

Reprography Unit, 91S, New Delhi, India

2